PRAGUE (Reuters) - Tennis's answer to golf's Ryder Cup will be as competitive as other global tournaments, 18-times grand slam champion Roger Federer said on Monday, dismissing concerns that players might treat the event, which launches in September, as an exhibition.

The Laver Cup format will be a rare chance to see the game's top players team up and Federer said he was most looking forward to appearing alongside long-time rival Rafael Nadal, who will also anchor the European side.

The tournament will see teams of six from Europe and the rest of the world compete in singles and doubles over three days, with four players selected on a "results-based formula" and two named as captain's picks.

Tennis greats Bjorn Borg and John McEnroe will captain the European and World sides at the event in Prague in September.

Federer, in the Czech capital to promote the tournament's ticket launch, said he did not think players would take the format lightly, despite not competing for rankings points.

"The idea is to absolutely have a tough tournament, tough matches - the better man wins," he told a news conference alongside Czech world number 14 Tomas Berdych.

"It has maybe no points and that is why people might consider it an exhibition. But that is not how the captains see it. That is not how Rod Laver sees it."

Each player will play at least one singles match, and a minimum of four of the six players must play doubles.

The competition, named after 77-year-old Australian Laver, the only player to win two calendar year grand slams among 11 major titles in all, will be annual, except in Olympic years.

It will rotate between major cities in Europe and the world while organisers have promised substantial prize money.

Nadal holds a 23-12 head-to-head record against Federer, although the Swiss beat the Spaniard in the Australian Open final this year to win a record-extending 18th grand slam title.

"I would love to play with Rafa just because our rivalry has been so special," Federer said.

"I have seen his wicked forehand go past me too often that it would be nice to have it on my team and actually admire his forehand and admire his shot-making."